Fire alarm



Aug. 27, 1929. W, T, BRU-3G55 1,726,013

FIRE ALARM l' Original Filed May 8, 1923 .215271311 y es I VENTOR wlTNEs'SEs b'wMa-wqanv 5? v BY ATTO RN EY Patented Aug. 27, 1929.

UNITEDY ls-"IArs 1,726,013 PATENT OFFICE.

WILLIAM T. BRIDGES, OF LA V:F.AYIE'I"TE, GEORGIA.

FIRE ALARM.

Original application-tiled May 8, 1823, Serial No. 637,527. Divided and this'applicatonled May 15,

1924. Serial No. 713,538.

This invention relates to a fire alarm system, which is especially adapted to be 1nstalled in a building, and is operable electrically upon the occurrence of iire to sound an alarm.

The present application is a division of an earlier application, Serial Number 637,527, iiledMay 8, 1923.

rfhe general object of the invention, as

lo herein claimed, is to provide a system which includes one or more local signals, such as an electric bell operable by a current of low voltage obtained by the interposition of a transformer between the same and the. servl5` ice wires, and, in combination therewith, a

loud alarm such as a siren, which may be mounted outside the building and operated by the service current, usually ot' 110 volts, the circuit through the siren being closed immediately upon the actuation-of they local alarm. f f

The above and other objects and advantages oi the invention will be more fully explained in the detailed description which follows, in conjunction with the accompanying drawing, which illustrates the preferred form of the invention.

In the drawing:

Figure 1 is a diagrammatic view showing :io the arrangement ofthe circuits used in c onnection with the installation vof the invention. Figure 2 is a detail view, partly in section, of the circuit closer for the high voltage circuit.

Figure 3 is a sectional view taken on the line 3 3 of Figure 2.

Figure 4 isan elevation of the circuit closer shown in Figure 2 looking from the inside.

Figure 5 is a detail sectional view of a circuit closer, which may be used in connection with the low voltage circuit.

In carrying out the invention, main lead wires 9 and 10 are connected to the service wires 11 and 12 respectively, and lead through a transformer 13 to various circuit closers 14 located in various parts of the building, which are so constructed that they will be closed when fire occurs in the vicinity. One of the lead wires, as 9, is connected with a local alarm, such as an electric bell 15, which is adapted to be rung immediately upon the closing of the circuit through the wires 9' and 10.

'as the bell 15 begins to ring.

The circuit closer 18, as shown in detail in Figures 2, 3 and 4, includes a cup shaped housing 19, having a. iianged rim 20 providyed with notches 21 through which the wires of the circuit 16 may pass, and secured to the wall of the building by suitable screws 22, or the like. Fitting within the housinfr 19 is a supporting plate 23 having outturnec ends 24, which are secured to the rim 20 by inturned ears 25 cut from said rim. An insulating block 26 is secured to the central portion of the plate, by means of inturned ears 27 cut from the plate. rBinding posts 28 and 29 are threaded into the block 26, and the open ends of the circuit 16 secured thereto. The binding posts 28 and 29 extend through openings 30` in the plate 23, and one of them, as 28, has a switch 31 pivoted thereto. This switchfextends'from its pivot normally above vthe other binding post 29 through a slot 32`in the housing'19, and its outer end 33 is composed ofnon-conductive material, and has a depending lug'34. The bell 15 is so located that its clapper 35 eX- tends underneath the outer portion 33 of the switch, and is oscillated downwardly and Y laterally when the bell is sounded. An eX- pansile coiled spring 36 normally rests at its lower end on the clapper 35, while its upper end receives the depending lug 34 and holds the switch open, as shown in Figure 2. Vhen the bellY circuitv is closed and the bell clapper vibrates rapidly, the spring 36 is jarred therefrom and releases the switch 31, which swings by gravity into contact with the binding post 29, and closes the circuit 16 and sounds the siren 17.

The circuit closers 14 may be of any approved construction, such that they will be closed when lire occurs in their vicinity. The preferred constructionl is illustrated in Figure 5, which shows a cup shaped housing 37, in which an insulating block 38 is supported in the same manner as the block 26 in thehousing` 19. Binding posts 39 are secured in the insulating block 38, and the wires 9 and 10 are connected thereto. The ends oi these binding posts 39 constitute-l spaced contact members, by the bridging of which circuit is established through the bell 15. rl`he housing 37 is formed centrally with a perforation surrounded by an inturned flange 40, within which is seated 'a movable contact member 41. This contact member has a cup shaped portion 42 which projects outwardly of the housing 37, and is normally held by a retaining pin 43. The inner portion ot the member 41 is provided with `a flat peripheral flange 44, which is adapted when released to bridge the contact members 39. An eXpansile coiled spring is seated within the housing 37 surrounding the flange 40 and presses Yagainst the iange 44, urging 1t toward the contact members 39. The pin 43 is made ot celluloid, lead or any other material, which will be fused or burned when subjected to i Alire. Consequently, when lire occurs, the pin 43 will be destroyed, thus releasing the movable member 41, which under the action of the spring 45 will be urged into position to bridge the contacts 39 and establish a circuit through the bell 15. Assoon as the bell begins to ring, the switch 31 is released and is closed by gravity, and the siren 17 is sounded.

It will be understood that any number ot circuit closers 14 may be located through` out .the building, and upon the occurrence oll lire in the vicinity ot any one ot them, the circuit through the bell 15 will be closed, and thc siren, as well as the bell, immediate ly sounded.

Vhile `I have shown and described specifically the detailed construction ot one form in which the invention may be carried out, it is to be understood that this is merely illustrative, and that various modifications may be made therein as long as such modiications do not constitute a material departure from the salient features of the invention. v

I/Vhat is claimed is:

1. In a tire alarm system of the class described having an electric bell therein provided with an oscillatable clapper, a circuit closer associated with the clapper comprising a pair of terminals; a switch arm pivotally connected to one of the terminals and normally held spaced above the other terminal yand operable by lgravity when released to engage the other terminal; and spring means interposed between the bell clapper andthe free end ot the switch to hold the latter open, said spring being' loosely held 'so as to be jarred loose by the vibration ot the bell clapper to close the switch.

2. In combination with the oscillatable clapper otl an electric bell of a tire alarm system, a circuit closervcomprising a housing; a pairot terminals in the housing; a switch pivotally connected to one ot said terminals and extending outwardly through a slot in the housing, the tree end of said v switch being spaced above the bell clapper and alsothe other terminal; means normally interposed between the clapper and the switch and supporting the latter in open position; said means being loosely held so as to be arred loose by the vibration of the bell clapper when said clapper is actuated to permit the switch to tall by gravity and en-V gage the otherl terminal.

In testimony, that I claim the foregoing as my own, I have hereto atHXed my signature.

I WILLIAM T. BRIDGES. 

